Radio and X-ray observations of the intermittent pulsar J1832+0029

TL;DR

This study reports on radio and X-ray observations of the intermittent pulsar J1832+0029, revealing long off-states, spindown rate variations, and challenging existing models of pulsar behavior.

Contribution

It provides detailed long-term observational data on an intermittent pulsar, highlighting its unique off-state durations and spindown rate ratios, and discusses implications for pulsar models.

Findings

Two long off-states lasting over 560 days each

Spindown rate ratio of 1.77 between on and off states

No X-ray emission detected during any state

Abstract

We report on radio and X-ray observations of PSR 1832+0029, a 533-ms radio pulsar discovered in the Parkes Multibeam Pulsar Survey. From radio observations taken with the Parkes, Lovell and Arecibo telescopes, we show that this pulsar exhibits two spindown states akin to PSRs B1931+24 reported by Kramer et al. and J1841-0500 reported by Camilo et al. Unlike PSR B1931+24, which switches between "on" and "off" states on a 30--40 day time-scale, PSR 1832+0029 is similar to PSR J1841-0500 in that it spends a much longer period of time in the off-state. So far, we have fully sampled two off-states. The first one lasted between 560 and 640 days and the second one lasted between 810 and 835 days. From our radio timing observations, the ratio of on/off spindown rates is $1.77 \pm 0.03$. Chandra observations carried out during both the on- and off-states of this pulsar failed to detect any emission. Our results challenge but do not rule out models involving accretion onto the neutron star from a low-mass stellar companion. In spite of the small number of intermittent pulsars currently known, difficulties in discovering them and in quantifying their behavior imply that their total population could be substantial.